Here at Precision Zone, one of our specialties is the repair services of Mitsubishi Inverter drive units. One series that we often work on is the Freqrol-A520/A540 series.

FR-A520/A540 inverters are offered in sizes ranging from 400W up to 55kW and have the option to use three-phase 200V or 400V input power. There are also country codes which designate the unit meeting U.S. specifications or European specifications, denoted by a “-NA” for U.S. or a “-EC” for European at the end of the unit’s model number.

There is an optional parameter unit, FR-PU04, which can be installed directly onto the unit or used remotely using an optional cable. This allows for easy access to parameters as well as monitoring faults. This series offers quite a few different stand-alone option units as well and this can range from external braking resistors to an optional power factor improving DC reactor. Please reference this excerpt from the manual for additional information on these optional units as well as common ways to connect them.

When assessing the functionality of a Mitsubishi General Purpose Inverter, our expert repair team of engineers and technicians conducts a four-step check:

1. Visual Overview Check

2. Static Test

3. Checks Under Power

4. Alarm Codes Verification

This overview is Precision Zone’s basic troubleshooting process. Once our repair team starts on the job, we use specialized and customized testing fixtures, Huntron trackers, signal generators, oscilloscopes, milli and megaohm meters, as well as any other necessary tools we have available to assure quality repair work. Most importantly, every repair is fully tested in our custom-built simulators under load with a motor to replicate real-life working environment.

Precision Zone goes as far as using heating chambers and overnight dynamic testing, when applicable, to guarantee performance of the repaired product when it arrives back with the customer.

Visual Overview

When conducting a visual check, the technician inspects the drive for any mechanical damage to the drive itself and any printed circuit boards (PCB). The technician then proceeds to verify connections are tight and correct inside the drive and there are no loose screws, wires or debris. Additionally, the unit is checked for any burn marks on the components, PCBs or chassis. During the visual inspection, excessive dirt on cooling components is noted as well as the functionality of the heat sink.

Basic Static Check

Input Module Testing

The input modules on these units can be tested by use of a digital multimeter with diode checking capabilities. Upon removing the cover, all of these terminals can be located along the terminal strip found within the unit.

Positive Lead

Negative Lead

Reading

R/L1

'P/+' Terminal

0.42V-.52V

S/L2

'P/+' Terminal

0.42V-0.52V

T/L3

'P/+' Terminal

0.42V-0.52V

'N/-' Terminal

R/L1

0.42V-0.52V

'N/-' Terminal

S/L2

0.42V-0.52V

'N/-' Terminal

T/L3

0.42V-0.52V

Output Module Testing

Using the same type of test as above, the output modules can be checked as well. These readings will vary slightly with drive capacity, but each reading should be within 10% of one another. Our technicians are also equipped with huntron devices further verify their integrity.

The list of alarms within the manual is a good starting point for troubleshooting the Mitsubishi General Purpose Inverters. If any additional troubleshooting assistance is needed for the FR-A520 or FR-A540, Precision Zone offers free technical support. Feel free to contact us via phone or email to get in touch with our experienced technical support team.

Learn the benefit of repairing your Mitsubishi FR-A500 of General Purpose Inverters with Precision Zone

Precision Zone, Inc. is not affiliated with, nor is an authorized distributor or representative of any manufacturer, brand or product listed on this web site, with the exception of those clearly identified as such. Designated trademarks, brand names and brands, appearing herein, are the property of their respective owners.